In general, a semiconductor fabrication method includes a deposition process of a wafer or an etching process of a wafer. In this process, the wafer is heated up to 500° C. to 700° C. by a resistor heater or a lamp heater under the condition that the wafer is loaded on a ceramic-made or metal-made susceptor.
In this case, in order to obtain process uniformity, a temperature distribution on the wafer needs to be uniformly adjusted, and, for this reason, the temperature of the susceptor needs to be uniformed.